Examining intendedness among pregnancies ending in spontaneous abortion

Spontaneous abortion (SAB) affects over 1 million US women each year, yet little is known about the intendedness of these pregnancies. We examined prevalence and correlates of unintended and unwanted pregnancies ending in SAB.

We used nationally-representative cross-sectional data of US women aged 15-44 from the 2011-2013 National Survey of Family Growth to examine pregnancies ending in SAB. We used modified Poisson regression models to evaluate associations between demographic and pregnancy characteristics with unintended and unwanted pregnancy.

Among 1351 pregnancies ending in SAB, 44.5% were unintended (i.e. unwanted or occurring sooner than desired). Younger women with SAB were more likely to report unintended pregnancies than women 30-44 years, and women 15-19 years reported unintended pregnancy most often [adjusted relative risk (aRR)=3.0; 95% confidence interval (CI): 2.2-4.1]. Unintended pregnancy was two times more likely among unmarried than married women [never married: aRR=2.2; 95% CI: 1.7-2.7; previously married: aRR=2.2; 95% CI: 1.7-3.0]. Other factors associated with unintended pregnancy were multiparity compared to nulliparity [aRR=2.6; 95% CI: 1.7-4.1 for ≥3 children; aRR=1.8; 95% CI: 1.3-2.5 for 2 children] and inter-pregnancy interval ≤12 months compared to >12 months [aRR=1.4; 95% CI: 1.2-1.7]. We found similar associations with unwanted pregnancies ending in SAB (15.3% of pregnancies). Neither race/ethnicity nor socioeconomic indicators were independently associated with unintended or unwanted pregnancy ending in SAB.

Many pregnancies ending in spontaneous abortion are unintended and/or unwanted. Women with pregnancy loss, like all reproductive-aged women, should receive comprehensive counseling about reproductive planning and contraception.

Similar to all pregnancies, nearly half of pregnancies ending in spontaneous abortion are unintended and/or unwanted, suggesting that many women experiencing spontaneous abortion may benefit from a review of family planning desires and the provision of reproductive planning counseling and effective contraception to prevent future undesired pregnancy.